/Engine/Source/Runtime/GeometryCore/Public/Operations/EmbedSurfacePath.h
Embed a surface path in mesh provided that the path only crosses vertices and edges except at the start and end, so we can add the path easily with local edge splits and possibly two triangle pokes (rather than needing general remeshing machinery) Also assumes triangles are only crossed over once (except possibly to loop around to the start triangle on the end triangle) Planar walks naturally create simple paths, so this function can be used on any paths created by single planar walks.
true if embedding succeeded.
*bool EmbedSimplePath ( bool bUpdatePath, [TArray](API\Runtime\Core\Containers\TArray)< int > & PathVertices, bool bDoNotDuplicateFirstVertexID, double SnapElementThresholdSq )